Nd^3＋离子掺杂YAG激光透明陶瓷的光谱性质及Judd-Ofelt理论分析

Spectroscopic Properties and Judd-Ofelt Theory Analysis of Nd:YAG Transparent Laser Ceramic

采用固相反应和真空烧结技术制备了掺杂浓度为1.0at%的Nd:YAG透明陶瓷样品,并测试了样品的吸收光谱和荧光光谱.样品在主吸收峰808nm处的吸收截面为3.10×10^(-20)cm^2,主荧光发射峰位于1064nm处,实测荧光寿命为257μs.应用Judd-Ofelt理论计算了Nd^(3+)在YAG中的强度参数Ω_λ(λ=2,4,6)、跃迁的振子强度、自发辐射跃迁几率、辐射寿命、荧光分支比等光谱参数.最后计算得到Nd:YAG透明陶瓷中Nd^(3+):~4F_(3/2)→I_(11/2)跃迁对应的受激发射截面大小为3.81×10^(-19)cm^2.结果表明:Nd:YAG透明陶瓷具有较大的受激发射截面和高的荧光量子效率(接近100%),是一种性能优良的激光材料.

Neodymium-doped yttrium aluminum garnet （Nd：YAG） transparent ceramic with doping concentration of 1.0at% was fabricated by a solid-state reaction method and vacuum sintering. The absorption spectrum and the fluorescence spectrum of the sample were measured. The highest absorption peak is centered at 808nm and the absorption cross section is 3.1× 10^-20cm^2. The main emission peak is at 1064nm, and the fluorescence lifetime is 257μs. The Judd-Ofelt intensity parameter Ωλ（λ=2, 4, 6）, spontaneous transition probability, fluorescence branching ratio and radiative lifetime of Nd^3＋ were calculated by Judd-Ofelt theory. Finally, the stimulated emission cross section of ^4F3/2 →^4 I11/2 transition calculated is 3.81×10^-19cm^2. It is found that the prepared Nd：YAG transparent ceramic has large stimulated emission cross section and high fluorescence quantum efficiency, which is a potentially excellent laser material.